title: The Caenorhabditis elegans intestine.
abstract: The transcriptional regulatory hierarchy that controls development of the Caenorhabditis elegans endoderm begins with the maternally provided SKN-1 transcription factor, which determines the fate of the EMS blastomere of the four-cell embryo. EMS divides to produce the posterior E blastomere (the clonal progenitor of the intestine) and the anterior MS blastomere, a major contributor to mesoderm. This segregation of lineage fates is controlled by an intercellular signal from the neighboring P2 blastomere and centers on the HMG protein POP-1. POP-1 would normally repress the endoderm program in both E and MS but two consequences of the P2-to-EMS signal are that POP-1 is exported from the E-cell nucleus and the remaining POP-1 is converted to an endoderm activator by complexing with SYS-1, a highly diverged β-catenin. In the single E cell, a pair of genes encoding small redundant GATA-type transcription factors, END-1 and END-3, are transcribed under the combined control of SKN-1, the POP-1/SYS-1 complex, as well as the redundant pair of MED-1/2 GATA factors, themselves direct zygotic targets of SKN-1 in the EMS cell. With the expression of END-1/END-3, the endoderm is specified. END-1 and END-3 then activate transcription of a further set of GATA-type transcription factors that drive intestine differentiation and function. One of these factors, ELT-2, appears predominant; a second factor, ELT-7, is partially redundant with ELT-2. The mature intestine expresses several thousand genes, apparently all controlled, at least in part, by cis-acting GATA-type motifs.
authors.affiliation: Department of Biochemistry and Molecular Biology, Alberta Children's Hospital Research Institute, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada. jmcghee@ucalgary.ca
authors.forename: James D
authors.initials: JD
authors.lastname: McGhee
mesh_terms: D000818:Animals; D001757:Blastomeres / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000254:growth & development* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004707:Endoderm / Q000254:growth & development / Q000378:metabolism; D050980:GATA Transcription Factors / Q000235:genetics / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000254:growth & development*; D008648:Mesoderm / Q000254:growth & development / Q000378:metabolism; D016601:RNA-Binding Proteins; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D050980:GATA Transcription Factors; C117258:POS-1 protein, C elegans; D016601:RNA-Binding Proteins; D014157:Transcription Factors; C073702:skn-1 protein, C elegans